On a mobile phone or a PDA (Personal Digital Assistant) that is driven by a battery, the power saving control function is widely used that moves the mobile phone or the PDA to a low power consumption state under a predetermined condition. For example, Japanese Patent Kokai Publication No. JP2005-142981A discloses a mobile communication terminal with multiple processors that places the application control CPU (ACPU), primarily used for application management control, in a low power state (power saving mode) when data processing is not performed and the communication control CPU (CCPU), primarily used for communication function management control, in a low power state (power saving mode) when data communication is not carried out (see paragraph 0006).
In addition, Japanese Patent Kokai Publication No. JP 2006-72991A discloses a configuration in which, in view of the fact that switching to the low power state (power saving mode), if performed too frequently, decreases the power consumption saving effect, the operation mode is switched considering a loss involved in the transition processing and return processing of the operation mode.
Patent Document 1:
Japanese Patent Kokai Publication No. JP2005-142981A
Patent Document 2:
Japanese Patent Kokai Publication No. JP2006-72991A